Hemacytometer Cell Counting Logic- by Prabhu (M.Tech Ph.D)

red square = 1.0000 mm², 100.00 nl
green square = 0.0625 mm², 6.250 nl
yellow square = 0.040 mm², 4.00 nl
blue square = 0.0025 mm², 0.25 nl
at a depth( height) of 0.1 mm.

1) For outer box (red)

Length of one big box (9 big boxes are in figure)= 1mm ie =0.1cm

Breath of one big box (9 big boxes are in figure)= 1mm ie =0.1cm

Height of one big box (9 big boxes are in figure)= 0.1mm ie =0.01cm

So volume of spore suspension in one big box is =0.1X 0.1X0.01

=10 ^-4 _mL³

10 ⁴ = conversion factor to convert 10 ^-4 _mL³ to 1ml

Formula

= No of cells X volume of square X DF

= No of cells X 10 ^-4 X DF

2) For outer box (yellow color )

Length of one box (16 boxes are in figure)=0.2mm ie =0.02cm

Breath of one box (16 boxes are in figure)= 0.2mm ie =0.02cm

Height of one box (16 boxes are in figure)= 0.1mm ie =0.01cm

So volume of spore suspension in one big box is =0.02X 0.02 X0.01

=10 ^-6 _mL³

10 ⁶ = conversion factor to convert 10 ^-6 _mL³ to 1ml

Formula

= No of cells X volume of square X DF

= No of cells X 10 ^-6 X DF

3) For outer small box (Green color )

Length of one box (25 boxes are in figure)=0.25mm ie =0.025cm

Breath of one box (25 boxes are in figure)= 0.25mm ie =0.025cm

Height of one box (25 boxes are in figure)= 0.1mm ie =0.01cm

So volume of spore suspension in one big box is =0.025X 0.025 X0.01

=6.25X10 ^-6 _mL³

6.25 x 10 ⁶ = conversion factor to convert 6.25 x10 ^-6_mL³ to 1ml

Formula

= No of cells X volume of square X DF

= No of cells X 6.25X10 ^-6 _mL³ X DF